There are many causes of chronic gastritis. The first is chronic gastritis caused by acid reflux, followed by the consumption of irritant beverages, eating irritating foods, and some medications that cause changes to the gastric mucosa. Bile reflux can also cause irritation and inflammation of the gastric mucosa. Other factors include changes in the environment, mental stress, and various irregularities in life, all of which can lead to chronic gastritis. If a patient experiences acid reflux, it is necessary to suppress stomach acid by administering acid-suppressing medications, as well as medications that protect the gastric mucosa to prevent chronic gastritis caused by acid reflux.